Microinvasive glaucoma surgery

iStent to reduce intraocular pressure.

A tiny implant helps the eye’s fluid drain through its natural outflow pathway. Depending on the approved iStent system and your individual condition, it may be implanted on its own or during cataract surgery if you also need treatment for a cataract.

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Tomas Engels, specialist in ophthalmology

Your specialist at Savignyplatz

Glaucoma surgery with Tomas Engels.

Tomas Engels offers micro-invasive glaucoma surgery with suitable iStent systems at our Savignyplatz practice.

As a specialist ophthalmologist, he will guide you through every stage of treatment: assessing whether the procedure is suitable for you, discussing your options, performing the operation and providing follow-up care. Whether the iStent is implanted on its own or during cataract surgery depends on your individual needs.

Savignyplatz practice Tomas Engels in the team

The procedure

A small bypass in the natural drainage pathway.

The eye continually produces aqueous humour, a fluid that nourishes important structures. It normally drains through the trabecular meshwork into Schlemm’s canal. If this drainage is restricted, pressure inside the eye can rise and permanently damage the optic nerve.

iStent is a family of tiny trabecular micro-bypass implants. Depending on the system used, one or more implants are placed from inside the eye through the trabecular meshwork into Schlemm’s canal, creating direct access to the eye’s natural drainage system.

The aim is to control eye pressure more effectively and, where medically possible, reduce the need for pressure-lowering drops. The procedure cannot reverse existing damage to the optic nerve and does not replace lifelong glaucoma monitoring.

Two treatment options

On its own or with cataract surgery.

The effect on the natural drainage pathway is similar. The surgical setting and the specific iStent system differ.

Stand-alone

An approved iStent system as a stand-alone procedure

This micro-invasive glaucoma procedure is performed separately from cataract surgery. The natural lens remains in place.

When can that make sense?

Eye pressure remains insufficiently controlled despite existing treatment.
Where possible, the aim is to reduce the burden of eye drops or problems with tolerating them.
There is currently no reason for cataract surgery.
The drainage angle and the eye’s other anatomical features are suitable.

Not every iStent product is approved for standalone surgery. If the natural lens remains, we also discuss lens-related risks using the specific system’s instructions for use.

Combined

iStent plus cataract operation

If cataract surgery is needed alongside suitable open-angle glaucoma, both conditions can be treated in one operation.

What happens during the procedure?

The cloudy natural lens is removed and replaced with a clear artificial lens.
The trabecular micro-bypass is placed in the drainage area during the same operation.
You do not need a separate second operation for the iStent.
In addition to treating the cataract, the combined procedure may affect eye pressure and the amount of medication needed.

Cataract surgery alone can change eye pressure. We therefore assess your glaucoma history to decide whether adding an iStent offers a worthwhile benefit.

The right choice is the medically appropriate option, even when it is less convenient.

We choose the approach according to glaucoma type and severity, target pressure, lens status, previous treatments and individual circumstances.

Individual suitability

Who is an iStent suitable for?

A single pressure reading is not enough to make the decision. We assess the whole clinical picture.

Glaucoma form

The natural drainage pathway must be accessible through an angle that is sufficiently open and clearly visible. The procedure is typically used for suitable forms of open-angle glaucoma.

Previous course of the condition

Eye pressure, visual field, optic nerve health and the response to previous pressure-lowering treatment help us decide whether surgery could be useful.

Medicines

Poor tolerance, difficulty using drops regularly or wanting fewer drops may be factors in the decision.

Condition of the natural lens

If you also have a cataract that needs surgery, an iStent system approved for this use may be implanted during the cataract operation. Without a cataract, a system specifically approved for standalone implantation may be considered if the clinical indication is appropriate.

Individual target pressure

Advanced glaucoma or the need for a very low target pressure may call for a different pressure-lowering operation.

Anatomy of the eye

Gonioscopy and examination of the front of the eye establish whether the drainage area can be reached safely.

From examination to follow-up

Careful planning and outpatient support

Careful planning matters just as much as the short micro-invasive procedure itself.

Careful diagnostics

We assess eye pressure, optic nerve, OCT, visual field, drainage angle, cornea and previous treatment.

Joint decision

We discuss goals, alternatives and whether to treat separately or combine treatment with cataract surgery.

Outpatient procedure

The implant is placed from inside the eye into its natural drainage area through a small corneal opening.

Follow-up checks and adjustments

After surgery, we check eye pressure and healing. Pressure-lowering medication is changed only on medical advice.

After the operation

The eye may be irritated initially. Temporary pressure changes or a small amount of blood in the front of the eye are also possible. Use prescribed drops as instructed.

Never stop your existing glaucoma drops on your own. Follow-up examinations show whether and how your medication can be adjusted. Keep your implant card permanently and show it at later examinations, especially before an MRI scan.

Balanced decision

Possible benefits, limitations and risks.

Every operation needs an individual assessment of benefits and risks and a clear explanation.

Possible benefits

Using the eye's natural aqueous humour drainage
A small opening in the cornea
No filtering bleb is formed under the conjunctiva
Outpatient treatment
May lower eye pressure and reduce the need for drops
May be combined with cataract surgery that is already needed

Boundaries

The amount of pressure reduction varies between patients.
A sufficiently low target pressure is not always achieved.
Eye drops may remain necessary.
Existing optic nerve damage cannot be reversed.
Further laser treatment or surgery may be needed later.

Possible risks

Temporary increase in pressure or low intraocular pressure
Bleeding in the front of the eye and inflammation
Blockage, malposition or displacement of an implant
Corneal, iris or lens injury
Infection, visual impairment or re-operation
Possible cataract progression after standalone surgery

This list does not replace a personal discussion of the procedure. Risks, MRI precautions and approved uses vary between implant systems. Before surgery, we will explain the instructions for the specific product proposed for you, the risks relevant to your eyes and the available alternatives.

Costs and reimbursement

Agree the details before proceeding.

Insurance coverage depends on the implant system, medical indication, whether it is combined with cataract surgery and the terms of your statutory or private policy.

We assess the proposed treatment individually and explain any need for insurer approval or personal contribution before surgery.

Frequently asked questions

What patients want to know.

Is the iStent noticeable in the eye?

The implant sits in the drainage angle inside the eye. You normally cannot see or feel it.

Can I do without eye drops after surgery?

Possibly, but it is not guaranteed. Glaucoma drops are reduced or stopped only if pressure checks show it is medically appropriate.

Is standalone treatment always better than combined surgery?

No. Standalone treatment is useful when cataract surgery is not needed. If a cataract also needs surgery, combining the procedures can address both goals in one operation.

Can I still have other glaucoma treatments?

Yes. Medicines, laser treatment or other operations may still be needed. The iStent is part of a long-term treatment plan.

Does the procedure cure glaucoma?

No. The aim is to lower or better control eye pressure to slow progression where possible. Existing optic nerve damage remains.

Medical note

This page is general information, not a substitute for an examination. We can choose an iStent variant and surgical approach only after full glaucoma testing and a personal consultation.

Medical basics